ANTIBACTERIAL ACTIVITY, BIOCHEMICAL COMPOSITION AND PHYTOCHEMICAL SCREENING OF SEAWEEDS SARGASSUM WIGHTII, CHAETOMORPHA CRASSA AND VALONIOPSIS PACHYNEMA
Anju T. Varghese and D. Vigneshpriya*
Now-a-days the importance of seaweeds has been increasing both for pharmaceutical industry and traditional users as they have biological activity. The present study was conducted to investigate the phytochemical and biochemical contents and antibacterial property of three different seaweeds such as Chaetomorpha crassa, Valoniopsis pachynema and Sargassum wightii collected from the coast of Mandapam, Tamil Nadu, India. Extracts of powdered seaweed were prepared using different polar and non-polar solvents (Distilled water, Ethanol and petroleum ether). The antibacterial activity of seaweeds was analyzed against human pathogenic bacteria like Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa and Klebsiella pneumoniae using agar well diffusion method. The extracts showed the presence of phytochemical constituents like flavonoids, tannins, phenols, sterols and terpenoids. The seaweed extracts were analyzed for the presence of carbohydrates, proteins and lipids. The brown alga Sargassum wightii contains lesser amount of carbohydrates (2.6 mg) as compared to the Chaetomorpha crassa (3.15 mg) and Valoniopsis pachynema (5.4 mg). The results indicated that among the tested extracts for antibacterial activity, Bacillus subtilis and Staphylococcus aureus were susceptible to ethanol and petroleum ether extract, whereas all the four bacterial isolates were resistant and moderately susceptible to aqueous extract. The result obtained from the study points out that the active component present in ethanol extract could prove to be a great remedy for treating diseases. The infections caused by Bacillus subtilis can be treated with acetone extract of seaweeds.
Keywords: Seaweeds; Biochemical; Phytochemical; Human Pathogens; Antibacterial activity.
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